At present, simulating an animal to perform a prone crawling motion is a new type of exercise and fitness method which becomes more popular in some countries. The main principles and functions that performing crawling movement can achieve good fitness effects may be explained as follows.
The essential difference between humanity and animal is that humanity is able to stand and walk erectly but animal is not. However, comparing with the animal which crawls with its four limbs, the humanity who stands and walks erectly has some defects in human body itself, among them the following two defects may be the essential.
First, the load condition of spine is unreasonable. The spine in human body is mainly composed of the cervical vertebra, the thoracic vertebra, the lumbar vertebra, the sacrum and the coccyx. From the mechanics of spine structure, human is not suitable for walking erectly. When human stands erectly, the weight of the head is mainly borne by the cervical vertebra and the weight of the upper body is almost entirely borne by the lumbar vertebra. Under the heavy load for a long time, the spine would easily produce distortion, dislocation, proliferation and prominent intervertebral disc and result in diseases. It can be seen that more and more people suffer from the cervical vertebra sickness, the lumbar vertebra sickness, the strain of lumbar muscles and various other kind of diseases related to spine.
Second, the blood flow direction is unreasonable. When human walks erectly, his trunk is vertical to the Earth. The blood flow direction from heart to brain is vertically upward. Owing to the gravity, the cardiovascular system consumes much more energy to move the blood. The blood returns from lower limb to heart is also difficult. Therefore, human tends to have the heart and brain blood vessel diseases.
However the crawling movement could change the unreasonable situations and overcome the defects owing to erect walk.
First, the mechanics structure and the load condition of spine could be changed in crawling pose. When crawling, the weight of whole body distributes to four limbs, therefore the load to the cervical vertebra, the thoracic vertebra and the lumbar vertebra would be reduced greatly. More importantly, when crawling, the spine restores to the reasonable mechanics structure condition. In other words, the spine is in its natural, free and relaxed S shaped horizontal position. In this position cervical vertebra, the thoracic vertebra and the lumbar vertebra are restored the normal physiological and anatomical structure position. Therefore, the diseases related to spine such as strain of lumbar muscles, the sciatica, the cervical vertebra sickness and the lumbar vertebra could be prevented or treated.
Second, the blood flow direction could be changed in crawling pose. When crawling, the blood flow direction from heart to head is nearly in parallel line with the horizon. At the same time, the majority of blood in whole body is nearly in same level with the heart. Compared with the vertical flowing of blood when standing or walking, the horizontal flowing of blood when crawling would be obviously more free and smooth, the artery and vein circulation would be more unobstructed, more sufficient, so the cardiovascular system does not have to consume more energy to satisfy the blood nutrition need in various parts of the human body, thus the work load of cardiovascular system is reduced greatly. This is beneficial to prevent and treat the heart and brain blood vessel diseases such as brain blood supply insufficiency and arteriosclerosis and so on. Crawling is the main movement which most animals perform when they walk, run, jump and dash. Therefore the reptile and other four-feet walking animals have very few diseases with their heart and brain blood vessels. In addition, due to the lower heart position, the blood in lower limbs returns to heart more easily, thus the lower limb varicosity and hemorrhoids could be prevented.
Moreover, the way of breathing is changed when crawling. When standing, human breathe primarily through the chest. However when crawling, human breathe primarily through the abdomen. In abdominal breathing, the vertical motion scope of diaphragm is increased, the pulmonary alveolus is expanded, all kind of internal organs and blood vessels in abdomen also move rhythmically along with the breath frequency, the vital capacity is enlarged, the cardiopulmonary function is enhanced. Crawling movement is really a good exercise for fitness. However, the crawling movement is restricted by the space and place. The movement intensity is also hard to control. Particularly when crawling in outdoor, it may cause the damage to hands and knees without proper protection.
As is well known in the art, at present most fitness equipments are designed for stand-up or sit-up use, such as treadmill, elliptical and rower. These kind of fitness equipments cannot eliminate and overcome the above human body defects when people is in the upright posture.
There are some fitness equipments which can be used by people in prone posture, such as push-up, wheeled exerciser in prone posture (Chinese patent number CN200610074574.9) and so on. However, these fitness equipments are mainly used for strength training and do not allow the user's four limbs moving co-ordinately in prone posture and cannot exercise the user's lower back and abdomen or lower limbs with different load. They are also not suitable for the infirm and elderly people, especially, the upper limb disabled people. An exercise apparatus “the cardiovascular spine exerciser” (patent number CN1618488A, GB0326735.8, issued in the name of Zinnur Akhmetov) allows the user to perform the exercise in prone posture based on “fourlimbs”. But the movement provided by this exerciser is not the crawling motion, it is just a four-limb swinging movement.